Courtesy of InfineonMunich:
3 µm deep anisotropic etch

RIE technology

OPT application lab:
10 µm deep GaAs/ AlGaAs etch

signal and first derivative from laser interferometry:
GaAs/ AlGaAs Heterostructure RIE
endpoint detection integrated in PC2000 software

Cl₂ based process
rate  50  - 150 nm/ min
selectivity 1 : 1
smooth walls
wall angle > 89°
mask: photoresist or SiO2, Si3N4
selectivity to PR > 5 : 1
selectivity to SiO, SiN > 10: 1
uniformity +/- 3 %

Plasmalab System 100
RIE with vacuum loadlock

Courtesy of InfineonMunich:
3 µm deep anisotropic etch